In an electronic component mounting machine that mounts electronic components onto a circuit board, since suction nozzles corresponding to the shapes, sizes, and the like of the electronic components are used, many suction nozzles are necessary. Therefore, a nozzle palette or the like that is capable of storing the suction nozzles is used, and the suction nozzles are managed in a state of being stored in the nozzle palette. In this case, it is necessary to detect the storage location of the suction nozzle in the nozzle palette or the like. Therefore, inspection is performed to determine whether a suction nozzle is stored in a nozzle storage section of the nozzle palette or the like. In the patent literature described below, a method is described in which reflected light is used to inspect whether a suction nozzle is stored in a nozzle storage section.